Vitamin B2 (Riboflavin)

Riboflavin is a water-soluble vitamin.
Its metabolism is controlled by different hormones which regulate its conversion in FAD (flavin adenine dinucleotide) and FMN (flavin mononucleotide). These two coenzymes catalyze many oxidation-reduction reactions and are essential for our production of energy.
Riboflavin is absorbed through the walls of the small intestine and is carried by the blood to the tissues of our body. Since it is a water-soluble vitamin, it cannot be stored, but small amounts of riboflavin can be found in the liver, heart and kidneys. Otherwise it is excreted in the urine, feces and sweat. Therefore, this vitamin must be provided daily through our diet.
Riboflavin is stable to heat, oxidation, and acid, but unstable in the presence of alkali compounds or light.

Roles
Riboflavin is crucial for the production of energy.
It helps the body release energy from carbohydrates but it also aids in the metabolism of fats and proteins.
Riboflavin is essential for normal growth and development, cell respiration, regulation of certain hormones, antibody production and for the health of the mucous membranes in the digestive tract. It participates in the making of red blood cells and maintenance of the body tissues (especially those of the skin and eyes). Vitamin B2 is necessary for good vision.
In addition, it is essential to the proper function of three other B vitamins (B6, B9 and niacin) and iron absorption. It may be helpful in the prevention and the treatment of cataracts.
Riboflavin is an antioxidant that works with glutathione reductase. Together they protect our cells against free radicals damage.

Intake
Extra might be needed when consuming alcohol, high protein diet, antibiotics, birth control pills or doing strenuous exercises.

Recommended Dietary Allowance (RDA)
mg per day
Babies 0 to 1 year
0.4
Children 1 to 3 years
0.8
Children 4 to 6 years
1
Children 7 to 9 years
1.3
Teenager boys 10 to 12 years
1.4
Teenager girls 10 to 12 years
1.3
Teenager boys 13 to 15 years
1.6
Teenager girls 13 to 15 years
1.4
Teenager boys 16 to 19 years
1.6
Teenager girls 16 to 19 years
1.5
Men
1.6
Women
1.5
Pregnant women
1.6
Nursing mothers
1.8

Deficiency symptoms
A deficiency in this vitamin is seldom in occidental countries. One's diet must provide really small amounts of riboflavin in order to observe deficiency symptoms.
Deficient people would develop skin and/or eyes problems.

Good vegetarian sources
The richest in the plant sources are sea vegetables (nori, dulse, kelp...) and nutritionnal yeast.
Good souces of vitamin B2 are green leafy vegetables (beet greens, spinach, mustard greens..), broccoli, avocado, mushrooms, peas...
Vitamin B2 can also be provided by legumes such as lentils, garbanzo beans, navy beans, soybeans and products made from soybeans...
We can also find this vitamin in whole grains, nuts and seeds: sunflower seeds, sesame seeds, pumpkin seeds, almonds, wheat germ and bran, millet...

Cautions
Riboflavin can be lost from foods during storage and cooking. In order to retain as much as possible this vitamin, store foods in containers through which light cannot pass.


Realized by Laurence LIVERNAIS-SAETTEL, Dietitian.
© Copyright L. Livernais-Saettel 2000
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